[Packages/Optimizations] Move all optimization logic in a dedicated file

optimizations.nix

@@ -0,0 +1,70 @@
+{ config, pkgs, lib, myLib, ... }:
+with lib;
+let
+  cfg = config.aviallon.optimizations;
+  desktopCfg = config.aviallon.desktop;
+  generalCfg = config.aviallon.general;
+
+  _optimizeAttrs = level:
+    traceValSeq ((myLib.optimizations.makeOptimizationFlags {
+      inherit level;
+      cpuArch = generalCfg.cpuArch;
+      extraCFlags = cfg.extraCompileFlags;
+    }) // {
+    preConfigure = ''
+      cmakeFlagsArray+=(
+        "-DCMAKE_CXX_FLAGS=$CXXFLAGS"
+        "-DCMAKE_C_FLAGS=$CFLAGS"
+      )
+    '';
+    doCheck = false;
+    doInstallCheck = false;
+  });
+  optimizedStdenv = pkgs.addAttrsToDerivation _optimizeAttrs pkgs.fastStdenv;
+  
+  optimizePkg = {level ? "normal" }: pkg:
+  (
+    if (hasAttr "stdenv" pkg.override.__functionArgs) then
+      trace "Optimized ${getName pkg} with stdenv" pkg.override {
+        stdenv = pkgs.addAttrsToDerivation (_optimizeAttrs level) pkgs.fastStdenv;
+      }
+    else
+      warn "Can't optimize ${getName pkg}" pkg
+  );
+in
+{
+  options.aviallon.optimizations = {
+    enable = mkOption {
+      default = true;
+      example = false;
+      description = "Enable aviallon's optimizations";
+      type = types.bool;
+    };
+    lto = mkEnableOption "enable LTO for some packages";
+    extraCompileFlags = mkOption {
+      default = [ "-mtune=${generalCfg.cpuTune}" ];
+      example = [ "-O2" "-mavx" ];
+      description = "Add specific compile flags";
+      type = types.listOf types.str;
+    };
+  };
+
+  config = mkIf cfg.enable {
+    nixpkgs.overlays = mkBefore [
+      (self: super: {
+        htop = optimizePkg {} super.htop;
+        nano = optimizePkg {level = "unsafe";} super.nano;
+        virtmanager = optimizePkg {} super.virtmanager;
+        libsForQt5 = super.libsForQt5.overrideScope' (mself: msuper: {
+          kwin = optimizePkg {} msuper.kwin;
+          dolphin = optimizePkg {} msuper.dolphin;
+        });
+        libsForQt514 = super.libsForQt514.overrideScope' (mself: msuper: {
+          kwin = optimizePkg {level = "unsafe"; } msuper.kwin;
+          dolphin = optimizePkg {} msuper.dolphin;
+        });
+        #wayland = optimizePkg super.wayland;
+      })
+    ];
+  };
+}